The present application claims priority under 35 U.S.C. xc2xa7119 to Japanese Patent Applications No. 11-160413, filed Jun. 8, 1999, and No. 2000-088691, filed Mar. 28, 2000. The contents of these applications are incorporated herein by reference in their entirety.
1. Field of the Invention
The present invention relates to a sheet sorting device which is attachable/detachable to/from a sheet discharging apparatus.
2. Discussion of the Background
Japanese Laid-open Patent Publication No. 8-91677 describes a sheet sorting device which sorts sheets discharged from an image forming apparatus such as a copying machine and a printer by shifting in a direction perpendicular to a sheet conveying direction by a predetermined stroke. The contents of this reference are incorporated herein by reference in their entirety.
The above-described sheet sorting device includes main elements such as an overall frame supporting a pair of sheet discharging rollers and a driving mechanism. The sheet sorting device is integrally provided with the image forming apparatus as a part thereof. Specifically, a sheet post-processing apparatus is attached downstream of a main body of the image forming apparatus in the sheet conveying direction, and includes the sheet sorting device therein. In the sheet post-processing apparatus, the sheet sorting device is provided at an intermediate position between a pair of sheet receiving rollers which is located at the most upstream side with respect to the sheet conveying direction to receive the sheets conveyed from the main body and a sheet discharging tray which is located at the most downstream side with respect to the sheet conveying direction.
In the above-described sheet post-processing apparatus, in a sort mode, the sheets are discharged to the sheet discharging tray via the sheet sorting device after passing through the sheet conveying path extending across the sheet post-processing apparatus. In a non-sort mode, the sheets are also discharged to the sheet discharging tray via the sheet sorting device without being sorted. In both sort and non-sort modes, because the sheets are conveyed across the sheet post-processing apparatus via the sheet sorting device, it takes time to discharge the sheets to the sheet discharging tray after receiving the sheets from the main body of the image forming apparatus.
In this type of image forming apparatus wherein a sheet post-processing apparatus including a sheet sorting device is attached downstream of the main body of the image forming apparatus in the sheet conveying direction, if a user who originally operates only non-sorting jobs and uses a sheet discharging tray without attaching the sheet post-processing apparatus, and if the user needs to operate sheet sorting jobs later, the user needs to attach the sheet post-processing apparatus including the sheet sorting device next to the main body of the image forming apparatus. As a result, the sheet post-processing apparatus occupies space.
Another background sheet post-processing apparatus for use in an image forming apparatus includes a sheet discharging tray having sheet sorting and stapling functions. Because the sheet sorting operation is performed in the sheet post-processing apparatus, a user who operates not stapling jobs but sheet sorting jobs needs to attach the sheet post-processing apparatus including devices both for sheet sorting and stapling to the image forming apparatus. Consequently, the user needs to attach the sheet post-processing apparatus of increased size.
The present invention has been made in view of the above-discussed and other problems, and an object of the present invention is to address these problems.
The preferred embodiment of the present invention provides a novel sheet sorting device and sheet discharging apparatus that can reduce a sheet conveying distance and time for discharging sheets to a tray.
The preferred embodiment of the present invention provides a novel sheet sorting device and sheet discharging apparatus wherein the sheet sorting device can be easily attached to the sheet discharging apparatus in a compact and space saving configuration.
These objects and others are achieved according to the present invention by providing a novel sheet sorting device for a sheet discharging apparatus which has a sheet discharging tray which receives discharged sheets when the sheet sorting device is not attached to the sheet discharging tray. The sheet sorting device includes a movable tray which is configured to receive sheets discharged from the sheet discharging apparatus and configured to reciprocate in a reciprocating direction substantially perpendicular to a sheet conveying direction of the sheet discharging apparatus by a predetermined stroke necessary for sorting sheets. The sheets are sorted by reciprocating the movable tray in the reciprocating direction. The sheet sorting device is configured to detachably attached to the sheet discharging tray.